Sasha, the workshop instructor demonstrates setting the level for the bricks that will form the oven floor and hearth at the opening.

A layer of firebricks forms the floor of the oven. Here we fit them tight together on a bed of sand, trying to leave no cracks or crevices for ash to accumulate. The fire will be built directly on this surface in the completed oven.

With a circle for the oven interior traced onto the bricks, we begin to layer the cob mixture (in the bowl) onto the foundation, around the bricks.

A mound of sand forms the shape that will be the interior of the oven. The sand mold will be removed through the oven door once the cob and plaster have dried.

Smoothing the sand mold with trowels to ensure a symmetrical and smooth interior to the curved oven walls.

Building the brick arch over a mold, to form the oven door. Bricks are mortared together with a simple clay-sand mixture.

Final smoothing of the sand mold. Mary fell in love with the plastering trowels and smoothing process during this workshop.

Participants begin building up the interior layer of the oven; the first layer is a dense clay-sand mixture, without straw.

Next, a layer of dense cob is built up, providing strong structural support and thermal mass to hold the heat of the oven.

After the dense cobb layer for thermal mass, we add a layer of straw coated with clay slip as a thick insulating layer.

A layer of plaster tops the insulation, protecting the oven and providing the smooth outer surface.

Smoothing plaster over the insulation layer. This is a stage where you can add sculptural details, though we kept this oven mostly smooth and simple.

The door of the finished oven from the workshop; as it dries, the sand will be scooped out through the door. Sasha will be able to cook with this oven within the next week.

During the workshop, we cooked in the older ovens at Quail Springs, enjoying pizzas, roasts, and cinnamon rolls prepared at different stages of the ovens' firing. Pizzas are the only thing cooked with the fire still inside; everything else is cooked after the fire is removed, just with the retained heat of the oven walls.

We brought some food gifts from our farm in Missoula to our friends at Quail Springs, and were honored to have our leg of lamb roasted in the earth oven and shared with residents there.

Traveling around the world, I am always amazed at how cool - literally comfortable - farmers' homes can be. On a trip to Cote d'Ivoire, on a project with the Rainforest Alliance, I accompanied farmers to fetch water from a neighboring diversified cocoa farm. While cocoa farms are known for their shade, the trees need regular care and pruning, so it's common for farmers' homes to not have as much shade as they might need during the heat of the day in West Africa. That day when we stepped from a hundred degree sun outside to the interior of an adobe brick hut, though, it was more than ten degrees inside. Later, back in the small town where I spent the night, my concrete hotel room was unbearably hot.

Earth building is not new. While small farms have made shelter and homes out of clay, straw and sand for years, there are still habitable apartment buildings dating back not just hundreds, but thousands of years, and still inhabited. Earth building, commonly known as cob, is taking off in the United States. From pioneers such as the Cobb Cottage company in Oregon, to our network of friends around the United States, there is a growing community of natural builders helping demonstrate that we can have useable structures, spaces, and homes that do not need to be expensive or rely on the industrial economy. While a typical US home might last a lifetime, for many Americans, owning a home can trap us in a cycle of debt.

Precisely for this reason, our own fascination with natural building, and a connection with farmers who utilize this incredible proven technology, we recently traveled to Quail Springs to take an earthen oven building workshop. While I've helped in using natural materials to construct shelters for farmers in Africa and Asia, nothing beats more hands on experience. While we intend to construct some cob buildings on our farm in the coming years, we cannot wait to build an oven. When our friends put out the word they were hosting a workshop to build an earthen oven, it was easy to decide we'd make the journey to California. We jumped at the chance.

Basic cobb building is an approximate mixture of 1 part clay, 2 parts sand, and straw (though the ratios change depending on the texture of each of your materials). For building walls or for adding layers of thermal mass and insulation, you vary the ratio. While in our cold climate of Montana, we may need more insulation, the basic building materials and methods vary only slightly.

Now that we are back in Montana, we are planning on building our own farm oven later this spring. We're itching to get our hands back into that earthen mix, but have to face up to the deeply frozen days coming our way, and will have to content ourselves with a few test-bricks mixed indoors, until we have the land and weather to work with in the spring. We've already talked about building some ovens with some great local partners. During our last night at Quail Springs, we cooked lamb we brought from Montana in one of their ovens. It could not have been a better way to end our trip.

Why we write. On our home farm, we see connections between what we do and the farmers and people we work with around the world. We share these adventures here to invite you into the learning and community, regardless of where you are located.